There has been known a noise reduction device for reducing a noise current passing through a power conversion device by turning on or off a semiconductor switching element which forms an inverter. (Refer to Japanese Patent Application Publication No. 2002-252985.) The power conversion device includes a converter connected to an AC (alternating current) power supply, an inverter connected to the DC (direct current) output side of the converter, and a DC smoothing capacitor connected to a DC intermediate circuit. The noise reduction device includes noise current detecting means for detecting a noise current, and noise compensated current supply means for generating a noise compensated current for reduction of the detected noise current, and supplying the noise compensated current to the power conversion device. The noise compensated current supply means includes a series circuit of a transistor and a Zener diode, in which the transistor is configured as an element to output a current under control of a detection signal from the noise current detecting means and has a withstand voltage lower than a voltage of the DC intermediate circuit.